It is widely known that many old people develop hardening of the arteries as they age. Arteries become stiffer, harder, and less flexible. What is not commonly known is that a hardened artery can increase the reading of the systolic blood pressure.
Blood pressure consists of two pressure levels measured in millimeters of mercury (mmHg). The diastolic blood pressure (the low number) exists between heartbeats. The systolic blood pressure, (the high number) occurs at the peak of each heartbeat.
A substantial amount of training is needed before nurses develop the skills to get consistent and comparable blood pressure readings using the arm cuff and stethoscope. Since diagnosis and medication often depend on the patient's measured blood pressure, there is a need for assured accuracy and repeatability. Many hospitals have switched to an Automatic Blood Pressure Machine, whose readings are independent of the skill or judgment of an operator.
If the method for measuring blood pressure is based on criteria that do not include the influence of a hardened artery, then blood pressure as read by the machine, or by doctors and nurses will be consistently in error for patients with hardened arteries, the very patients where accuracy is most needed.
The present method of measuring blood pressure, whether by man or machine, follows the ancient procedure of pumping up an arm cuff to a relatively high pressure to be certain it is above the systolic blood pressure of the patient. A slowly falling column of mercury (indicating pressure) is closely watched while listening to a stethoscope for a first faint audible pulse to identify the systolic blood pressure, and the last faint audible pulse to identify the diastolic blood pressure.
This procedure with cuff, stethoscope and a falling column of mercury is the standard against which blood pressure machines may be compared for accuracy. The invention described below identifies the contribution of a hardened artery that causes consistently false high systolic blood pressure readings by blood pressure measuring machines, or by a doctor using a falling column of mercury.